Shotgun shells and method of forming hulls for shotgun shells



J. R. HALL June 30, 1970 SHOTGUN SHELLS AND METHOD OF FORMING HULL-S FOR SHOTGUN SHELLS Filed March 18, 1968 2 SheetsSheet 1 I I 4 ll/ Jofin f/a Mzywmy BY ii MWO/V/VEVJ June 30, 1970 J. R. HALL SHOTGUN SHELLS AND METHOD OF FORMING HULLS FOR SHOTGUN SHELLS Filed March 18, 1968 2 Sheets-Sheet 2 f0fi0 f1. f/a

INVENTOR BY /96 E J; WW

ATTORNEYJ United States Patent 3,517,617 SHOTGUN SHELLS AND METHOD OF FORMING HULLS FOR SHOTGUN SHELLS John R. Hall, P.0. Box 45901, Houston, Tex. 77045 Continuation-impart of application Ser. No. 589,014, Oct. 24, 1966. This application Mar. 18, 1968, Ser.

Int. Cl. F42b 7/06 US. Cl. 102-42 Claims ABSTRACT OF THE DISCLOSURE A shotgun shell and hull, and method for forming the hull, made entirely of a plastic material and having its discharge end sufliciently thin for slight rolling radially inwardly to retain the over-shot wad and other shell components within the hull. An over-shot wad means including a generally tubular portion having an outside diameter approximately equal to the inside diameter of the hull and having a general conical closure portion spanning the interior of the tubular portion from or near one end of the tubular portion.

Cross-references to related application This is a continuation-in-part of application Ser. No. 589,014, filed Oct. 24, 1966, now abandoned.

Summary This invention relates to new and useful improvements in shotgun shells and in methods of making or forming hulls for shotgun shells.

It is an object of this invention to provide an improved shotgun shell which includes a unitary or one-piece hull which may be readily formed by injection molding and does not need or require a separate base or cap of a different material.

It is another object of this invention to provide an improved shotgun shell of the character described in Which the hull is sufficiently deformable at its discharge end or mouth to permit repeated rolling of the edge of the mouth whereby the hull is suitable for reloading and in which the base of the hull is sufiiciently strong so as to remain substantially undamaged during firing and extraction of the spent hull from the breech of the shotgun.

It is another object of this invention to provide an improved hull for a shotgun shell of the character described wherein the hull is formed of polycarbonate resin by injection molding using commercially available injection moulding equipment.

It is another object of this invention to provide an improved method of forming a unitary or one-piece hull for a shotgun shell, the hull being formed of a plastic material.

It is another object of this invention to provide an improved method of the character described wherein the hull is formed by injection molding polycarbonate resin.

It is another object of this invention to provide an improved closure means for a shotgun shell in the form of an over-shot wad which requires only slight rolling of the mouth of the shell rather than crimping so that damage to the hull during firing is reduced to a minimum.

It is another object of this invention to provide an improved closure means in the form of an over-shot wad which remains substantially coaxial with and substantially perpendicular to the barrel of the shotgun as the Wad passes through the barrel so that the possibility of an undesirable shot patern due to tilting or cocking of the over-shot wad is substantially reduced.

Patented June 30, 1970 ice Brief description of the drawings FIG. 1 is a cross-section illustration of a unitary hull for a shotgun shell construction in accordance with this invention;

FIG. 2 is an illustration partially in cross-section of a shotgun shell constructed in accordance with this invention including the hull illustrated in FIG. 1;

FIG. 3 is a cross-section isometric view of the closure means or over-shot wad constructed in accordance with this invention;

FIG. 4 is an enlargement of a portion of the crosssection of the discharge end of the shotgun shell of FIG. 2;

FIG. 5 is an enlargement of a portion of the cross section of the discharge end of the shotgun shell such as in FIG. 4 but after the shell has been discharged to illustrate the substantial straightening of the hull; and

FIG. 6 is an enlargement of a portion of the discharge end of the hull such as in FIG. 4 but after the hull in FIG. 5 has been reloaded.

Description of the preferred embodiments In the drawings, the numeral 10 designates a unitary or one-piece hull 10 which includes a relatively thinwalled tubular portion 11 and a relatively thick rigid base portion 12 formed integrally with the tubular portion 11 at one end of the tubular portion 11. The discharge end or mouth 13 of the tubular portion 11 opposite the base portion 12 is open to permit loading or discharge of the shell components into or out of the hull 10.

The base portion 12 has formed therein a primer retaining means 14 into which the primer and primer battery cup may be inserted and held in place. An annular extraction flange 15 around the periphery of the base portion is formed integrally with the base portion so that the complete hull 10 is a unitary structure. The extraction flange 15 is provided so that the hull 10 may be withdrawn or extracted from the breech of the shotgun after the shell is fired. Therefore, the extraction flange 15 is subjected to rigorous use and must be sufliciently strong to withstand the extraction forces without breaking. Similarly, the base portion 12 is sufficiently thick to provide the required strength to withstand the forces encountered during loading of the shell as well as the high impact or shock forces generated during firing of the shell. This construction eliminates the need for a separate metallic cap about the base of the hull 10.

As illustrated by FIG. 2, the wall of the tubular portion 11 which forms the mouth or discharge end 13 is sufficiently thin in crosssection so that at least a part of the mouth 13 may be rolled slightly inwardly to retain the shell components within the hull after loading. As illustrated by FIG. 5, the mouth 13 is then straightened and the slight roll removed when the shell is fired or discharged, and the mouth 13 must then be rerolled during reloading as illustrated in FIG. 6. It is also desirable that the wall of the tubular portion 11 taper slightly along the interior surface 11b from the base portion 12 to the mouth 13. For instance, the wall thickness at or near the base portion 12 might be on the order of 0.050 inch and the thickness at the mouth 13 on the order of 0.030 inch to provide a 0.020 inch taper. Preferably, the outer surface 11a of the tubular portion 11 is relatively parallel to the centerline or axis of the hull so that substantially all of the taper is provided by the interior surface 11b.

The hull 10 is formed of a material which will protect and retain the components of the complete shell and yet withstand the rough treatment to which it is subjected during manufacturing, loading, handling, firing and reloading. Also, the material must be suitable for injection mold- In order to meet these requirements, the hull 10 is formed of polycarbonate resin. This material has the necessary physical, thermal ad chemical properties so that it may be readily formed by injection molding while providing the necessary strength and deformability characteristics. One such polycarbonate resin which is available commercially at the present time is marketed under the trademark Lexan by General Electric Company.

The hull 10 may be formed of a plastic material (polycarbonate resin) by injection molding without any additional treatment, such as molecular orientation, to gain the required strength. During injection molding, the base portion 12 of the hull 10 including the integral extraction flange 15, is formed with sufiicient thickness for the strength to withstand rough handling, loading, firing and extraction of the hull. As has been noted, forming the base portion in this manner eliminates the need for an additional metallic base or cap, including the extraction flange, about the base portion of the hull.

The tubular portion 11 is also formed during the injection molding operation. It is formed integrally at one end with the base 12 so that a unitary single-material hull is provided. The other end or mouth 13 of the tubular portion 11 is formed with a sufficiently thin cross-section so that at least a part of the mouth 13 may be rolled slightly radially inwardly to retain the components of the complete shell within the hull 10, as illustrated in FIGS. 2 and 4, and so that the rolled part is sufiiciently deformable that it tends to straighten, as illustrated in FIG. 5, without tearing during firing and discharge of the shell components out of the hull 10 through the mouth 13. Since the mouth 13 remains substantially intact after firing and there is little or no tearing or blowing away of the mouth 13, the hull 10 may be subsequently reloaded and the mouth 13 rerolled to retain the components with in the hull, as illustrated in FIG. 6.

As best seen in FIGS. 2, 4 and 6, by slightly rolling is meant curving of about 3045 from vertical and not more than 90 from vertical with a substantially large radius of curvature, such as a radius of about one-eighth inch. As is more fully explained hereinafter, this slight rolling is to be distinguished from crimping or folding over of the discharge end of the hull as was done in the prior art. Crimping or folding causes one or more sharp bends or breaks in the hull at or near the discharge end which frequently results in damage to the discharge end of the shell, and particularly that part which is crimped or folded over, to such an extent that that hull is not suitable for reloading and must be discarded. However, slightly rolling the discharge end 13 radially inwardly produces a smooth curved or sloping interior surface without any sharp bends or breaks and permits the discharge end 13 to substantially straighten when the shell is discharged without tearing of the discharge end 13 so that the hull 10 may be reloaded repeatedly.

As illustrated in FIG. 2, the complete shotgun shell includes the hull 10 into which the various shell components are loaded. The priming means 21 in the form of the usual primer battery cup containing the primer is inserted in the primer retaining means 14 and is preferably held in place by wedging or frictional engagement with the retaining means. 14 so that it may be readily re- .rnoved after firing for replacement during reloading.

The'various'shell components which are loaded into and contained by the hull 10 include the powder charge 22 disposed adjacent the primingmeans 21 so that the powder may be ignited when the shell'is fired. Overpowder wad means 23 is provided; over the powder charge 22 for the customary purposes of providing a gas seal and a shock absorbing cushion. The over-powder wad means 23 may. comprise one or more parts or combinations of parts for these purposes.

The shot charge 24 is disposed over the wad means 23 and comprises one or more and usually a large number of individual pellets. If desired, the shot charge 24 may be contained within a well-known shot sleeve or wrapper (not illustrated) disposed between the interior surface 11b of the hull 10 and the shot charge 24. Also, such a shot sleeve or wrapper may be formed as part of the overpowder wad means 23.

A closure means is disposed over the shot charge 24 to hold the components, and particularly the shot charge 24, in place in the hull 10. As noted above, the closure means is held in place over the shot charge by slightly rolling or deforming at least a part of the mouth 13 radially inwardly as illustrated in FIGS. 2 and 4. As is discussed more fully hereinafter, the mouth 13 should not be crimped or folded completely over.

As best seen in FIG. 3, the closure means is in the form of a top or over-shot wad 30 having a tubular wall portion 31 and an interior closure portion 32. The overshot wad 30 is preferably injection molded from a suit- .able material, such as polyethylene, which resists tearing and which is sufficiently pliable and resilient so that the wad functions satisfactorily. The tubular wall portion 31 has an appreciable axial dimension to provide enough axial wall surface in contact with the interior surface 11b of the hull 10 to prevent tilting or cocking of the top wad 30 in the hull 10 or in the barrel of the shotgun as it passes through the barrel after the shell is fired.

The interior closure portion 32 of the top wad 30 spans and closes off the space through the tubular wall portion 31 to complete the closure across the discharge end of the shell 20. The interior portion 32 has the general configuration of a low cone, the apex of the cone being at the centerline of the hull 10 and the tubular portion 31 of the top wad 30, and the base of the cone being formed integrally with the tubular wall portion 31. The over-shot wad 30 is positioned over the shot charge 24 so that the apex of the cone is pointed toward the mouth 13 of the hull 10 and away from the shot charge 24. Thus, when the shell is fired, the forces acting on the underside of the cone tend to force its base radially outwardly and force the outer surface of the tubular wall portion 31 into engagement with the interior surface 11b of the hull 10 and into engagement with the interior of the barrel of the shotgun after the wad is discharged from the hull. These forces tend to keep the over-shot wad 30 in axial alignment with the hull and barrel to prevent tilting or cocking of the top wad.

In a hull 10 formed of polycarbonate resin, if the mouth 13 is fully crimped over the shot charge so as to eliminate the need for an over-shot wad, then the material tends to tear away when the shell is fired so that it is not suitable for reloading. Similarly, if the mouth 13 is folded inwardly and over to such an extent that the edge of the mouth 13 faces the base portion 12 to hold the top wad in place, then there is the danger of excessive pressure being developed upon firing, and at least a portion of the mouth 13 will be blown away during firing so that the hull is not satisfactory for reloading. If a relatively thin top wad with a small axial dimension is placed over the shot, and the mouth 13 rolled slightly radially inwardly, then the thin top wad may cock or tilt in the tubular portion 11 of the hull so that at least some of the shot or other components may be lost. Also, such a thin wad might cock or tilt after the shell is fired as the shot charge and wad pass through the barrel which may result in an undesirable shot pattern. Thus, by using the over-shot wad 30 and by slightly rolling the mouth 13 of the hull 10 radially inwardly as illustrated in FIGS. 2, 4 and 6, over-shot wad 30 is held in its proper position in axial alignment with the hull 10, and the mouth 13 is straightened sufiiciently during firing for discharge of the shell components as illustrated in FIG. 5 without tearing of the mouth 13 so that the hull 10 may be reloaded. Also, the slight inward rolling of the mouth 13 as disinguis'hed from crimping permits more effective no energy is dissipated in unfolding the crimped end of utilization of the pressures generated during ignition since the shell.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1, The method of forming a complete unitary hull for a shotgun shell of a plastic material having a closure means of a composition and structure which presents a yielding surface to the end of said hull opposite the base portion of said hull so as to not present any substantial resistance to the inward rolling of said opposite end of said hull, said method comprising utilizing injection molding to produce the complete unitary hull,

forming during the injection molding step a base portion including an integral extraction flange hav ing sufficient thickness to withstand the forces en countered during handling, loading, firing and extraction of the hull,

also forming during the injection molding step a tubular portion integral at one end thereof and being in one piece with said base portion,

inserting conventional shotgun shell components within said hull including said closure means,

forming the end of the tubular portion opposite the base portion with a sufficiently thin crosssection to permit slight radial bending thereof,

slightly cold rolling radially inwardly at least a portion of said opposite end against at least a portion of said closure means without relying on the closure means as a mandrel,

said rolled hull portion and closure means retaining the shotgun shell components within the hull prior to firing said shotgun shell while permitting the discharge of the shotgun shell components upon the firing thereof with minimum damage to said oppo site end of said hull, and

cold rerolling slightly radially inwardly said portion of said opposite end during reloading of the shell to retain the reloaded components within the hull.

2. As a sub-combination in a shotgun shell which includes a tubular hull containing a powder charge, overpowder wad means and a shot charge, an over-shot wad means for disposing near the discharge end of said hull and over said shot charge as set forth in claim 1 wherein said generally conically shaped closure means spans the interior of said thin-walled tubular means from near the end of said tubular means adjacent said shot charge in a direction radially inwardly and away from said shot charge to substantially form a cone having its apex at the longitudinal centerline of said tubular means.

3. A unitary hull for a shotgun shell including an over-shot wad having a composition and structure which presents a yielding surface to the mouth end of said hull so as to not present any substantial resistance to the inward rolling of the mouth end of said hull comprising a tubular portion, and

a base portion formed at one end of said tubular portion,

said tubular portion having a mouth end at the end opposite said base portion through which the components of the shotgun shell may be discharged,

said base portion having extraction rim means formed thereon whereby said hull may be extracted from the breech of a shotgun,

said base portion having primer retaining means formed therein,

said base portion and extraction rim means having suflicient thickness and rigidity to withstand the forces encountered during handling, loading, firing, extraction, and reloading, and

means forming part of said month end for repeated cold rolling of a portion of said mouth end slightly inwardly without relying on the over-shot wad as a mandrel against which said mouth end is rolled.

4. A shotgun shell comprising a tubular hull formed entirely of a plastic material,

said hull having a base portion including an extraction flange at one end thereof,

said hull having an open discharge end opposite said base portion,

priming means disposed in said base portion,

a powder charge disposed within said hull adjacent said priming means,

over-powder wad means disposed over said powder charge,

a shot charge disposed over said over-powder wad means, and

over-shot wad means disposed near said discharge end of said hull and over said shot charge,

said discharge end being rolled slightly inwardly to retain said over-shot wad means in place prior to firing said shotgun shell,

said over-shot wad means having a composition and structure which presents a yielding surface to said discharge end so as to not present any substantial resistance to the inward rolling of said discharge end,

said slightly inwardly rolled discharge end being substantially straightened upon firing of the shotgun shell and passage therethrough of said over-shot wad means, shot charge and over-powder wad means with minimum damage to said discharge end of said hull.

5. A shotgun shell comprising a tubular hull formed entirely of a plastic material,

said hull having a base portion including an extraction flange at one end thereof,

said hull having an open discharge end opposite said base portion,

priming means disposed in said base portion,

a powder charge disposed within said hull adjacent said priming means,

over-powder wad means disposed over said powder charge,

a short charge disposed over said over-powder wad means,

over-shot wad means disposed near said discharge end of said hull and over said short charge,

said discharge end being rolled slightly inwardly to retain said over-shot wad means in place prior to firing said shotgun shell,

said slightly inwardly rolled discharge end being substantially straightened upon firing of the shotgun shell and passage therethrough of said over-shot References Cited wad means, shot charge and over-powder wad means UNITED STATES PATENTS 'd d' h d f 'd minimum damage to sa1 1sc arge en 0 sa1 347,051 8/1886 Libbeysaid over-shot wad means having a relatively thin- 5 3,147,709 9/1964 Wernerwalled tubular portion in engagement with the in- FOREIGN PATENTS terior surface of the tubular hull, and

said over-shot wad means having a generally conically shaped closure portion spanning the interior of said tubular portion,

said conical closure portion being so disposed that the forces applied to said overshot wad means during firing of said shotgun shell tend to force the thinwalled tubular portion of said over-shot wad means radially outwardly. 1

ROBERT F. STAHL, Primary Examiner US. Cl. X.R. 

